It's unlikely to be actively guided remotely. It's likely a small sensor package in the bullet itself. I imagine a simple passive guidance system akin to one

It's unlikely to be actively guided remotely. It's likely a small sensor package in the bullet itself. I imagine a simple passive guidance system akin to one of the early MANPADS (i.e., Redeye or Strela-2), but, using a laser designator instead of target radiated infrared.